Liquid crystal display (LCD) has been widely used in daily life, and a voltage mode transmitter (TX) is commonly used in a timing controller within the LCD panel. As the resolution of the LCD panel increases, the amount of transmission data required for the timing controller increases as well. Thus there may be higher data rate or additional ports required for the voltage mode transmitter. In addition, there are various applications of the LCD panel having different design requirements. For example, a larger panel may need a larger driver signal swing to overcome channel attenuation. On the other hand, a smaller panel may need a smaller signal swing to reduce power consumption. Therefore, it is an important subject in the industry to design a voltage regulator for supplying power to the voltage mode transmitter in order to meet a variety of design requirements.